Heat transfer apparatus



March 7,1967; J. K. WHIVSNANT ETAL Q 3,

' HEAT TRANSFER APPARATUS FiledDec. 29, 1964 s Sheets-Sheet 1 Afro/nayMarch 1967 J. K. WHISNANT YETAL 3,307,621

HEAT TRANSFER APPARATUS Filed Dec. 29, 1964 3 Sheets-Sheet 2 //vl//v70/?5 Jahn A. Wh/snarz/ Roger A. Dyson Afro/nay March 19.67 J. K.WHISNANT ETAL 3,307,621

HEAT TRANSFER APPARATUS Fil ed Dec. 29, 1964 3 sheets sheet 3 //VVE/VTORS John K W/v/snon/ Roger A Oysar/ A Nor/76y United States Patent3,307,621 HEAT TRANSFER APPARATUS John K. Whisnant and Roger A. Dysart,Shelby, N.C., assignors to Fiber industries, Inc., a corporation ofDelaware Filed Dec. 29, 1964, Ser. No. 421,808 Claims. (Cl. 16589) Thisinvention is directed to an improved heat transfer apparatus. Moreparticularly, the invention is directed to an improved unit of uniformlyheated rolls and to an improved heat transfer roll.

In the production of synthetic fibers, the extruded polymers such asnylon, polypropylene, polyethylene terephthalate in the form offilaments, generally, do not at this stage have the desired physicalproperties for suitable use in their final fiber form for the productionof fabrics in the textile or industrial areas. These extruded filamentsmust be further processed to impart full strength, durability, deniercontrol and the like. One important part of this further processing isknown as drawing or drawtwisting which includes stretching the yarn,twisting, kinking or texturizing. All of these stretching operationsshould be performed under precisely controlled temperature conditions.

The most critical problem in performing these operations is to heat theyarn to the desired temperature level to properly relax the longmolecular chains resulting in maximum strength and stability. Theequipment widely used to accomplish this purpose is stationary heatedplatens or blocks to heat the fibers. These methods of heating fibershave considerable disadvantages of short contact times and problemscreated by friction, among others.

Attempts to overcome these problems have been directed to the heating ofthe yarns on the draw rolls but this procedure has not been completelysatisfactory because of the difficulty of temperature control. The usualmethod of heating rolls is by electrical heating units with suitablecontrols in each individual roll and transfer of heat through a shortspace of air. Under these conditions, it has been found difficult tocontrol the temperature precisely. The thermal lags of heat transfer tothe roll are formidable and are the major deterrent to the approach. Toovercome these problems, numerous unsuccessful attempts have been madeto provide uniformly heated rolls for the drawing or draw-twistingoperations.

It is the object of this invention to provide unique and economicallyattractive units of uniformly heated rolls which overcome thepredominant disadvantages of the above-described heated rolls. A furtherobject is to provide an improved heat transfer apparatus which makes upan individual part of the units of uniformly heated rolls.

Other objects and advantages will become more apparent to those skilledin the art by reference to the disclosure of the preferred embodimentsin the specification, claims and drawings in which:

FIGURE 1 represents a perspective schematic of a unit of heated rollsarranged in series as used in a drawtwister operation;

FIGURE 2 is a cross-sectional side view of an individual heated roll inthe unit of heated rolls of FIGURE 1;

FIGURE 3 is a front-sectional view taken along lines 3-3 of FIGURE 2.

FIGURE 1 represents a draw-twister apparatus incorporating a unit ofuniformly heated rolls as claimed. The main inlet means 10 for the flowof heat conducting materials from the heating source, as indicated inthe drawing, supplies the heating means under a slight pressure to theplurality of feeder rolls 11 through the individual inlet means 12 tothe heating core within the rotatable or feeder rolls 11. The heatconducting material is withdrawn from the heating core through theindividual outlet means 13 by means of the differential of pressure ofthe heat conducting material in the main inlet means 10 and individualinlet means 12 to the main outlet means 14. Through the main outletmeans the heat conducting material is returned to the heating source, asshown. It should be noted that the excess heat conducting material whichdoes not pass through the heating core to heat rollers 11 is returned tothe heating source through line 10 along with the material used to heatthe rollers 11. If it is'desired, heating elements 15 such as indicated,can be included at appropriate places on the main inlet and outletlines. Bobbins of undrawn yarns are arranged in such a manner so as topermit the undrawn yarn to pass over the individual heated rollers 11and to pass on to its respective unnumbered roller which is running at ahigher speed than the heated rollers 11 to provide a stretching effectof the yarn to provide strength properties. The string-up of the yarnfrom the feed bobbin to the collection bobbin is described in the priorart and has not been shown in FIG- URE 1 in order to avoid confusionwhileemphasizing the method of heating a plurality of rolls.

FIGURE 2 represents a cross-section of a preferred embodiment of theimproved individual heat transfer apparatus as claimed herein which canbe used in the unit as described in FIGURE 1. A hollow rotatable roll 16which can be used primarily for heating filamentary material by passingthe yarns or filaments over or around the outside surface of the roll16, has a connecting rotatable shaft 17 to provide the desired rotatingmovement. A back plate 18 is attached to the rear portion of the hollowrotatable roll 16. The back plate 18 has an annular trough 19 extendinginwardly toward the hollow portion of the roll 16. The back plate 18 isshaped in such a way so that a drip ring assembly 20 which is placed onthe stationary heat radiating core 21 will prevent the escape of theheat conducting material 22 from the inside of the hollow portion ofroller 16. The stationary heat radiating core 21 is projected within thehollow portion of roller 16 and the core 21 is shaped so as tosubstantially conform to the hollow shape of roller 16 and at the sametime surround the rotatable shaft 17. Within the heating core 21 is apassageway 23 for the flow of heat conducting materials which in turnheats core 21. The flow of heat conducting materials for the heating ofcore 21 is introduced from the main inlet means (not shown) through theinlet means 24 and is removed to the main outlet means (not shown)through the outlet means (not shown) in FIGURE 2. The flow of the heatconducting means through the passageway 23 of core 21 transfers the heatthrough core 21 to the heat conducting material 22 which intimatelycontacts the outer portion of the stationary heat radiating core 21 andthe inner wall of the hollow rotatable roll 16. The heat conductingmaterial 22 is uniformly distributed by centrifugal force on the turningof the roll 16. It should be noted by this system, that an extremelyhigh efiiciency of heat transfer is available since there are no airspaces to hinder or disrupt the heat transfer. A guard 25 is placedaround the back plate 18 of rotatable roll 16 to prevent the heatconducting material 22 from escaping from the roll 16 and contaminatingthe products being heated on the outer surface of roll 16.

FIGURE 3 is a front-sectional view taken along lines 33 of FIGURE 2showing the inlet means 24 for the flow of heat conducting materialsconnecting with passageway 23 and passing out at the outlet means 26. Itshould be noted that the non-vapor heat conducting ma terial 22 withinthe rotatable roll 16 is maintained between the inner Wall of roll 16and the outer portion of the stationary heat radiating core 21 in auniform layer by centrifugal force on the rotating of roll 16. When roll16 ceases to rotate, a reservoir 27 is available for the nonvapor heatconducting material 22.

The materials which can be used in the manufacture of the rotatable rolland the heat radiating stationary core can include those materials whichreadily transfer heat and are known in the art for roller productionsuch as mild steel, stainless steel, aluminum, brass, etc.

The heat conducting materials which can be utilized in the rotatableroll are non-vapor materials including suitable and preferably liquidssuch as high temperature resistant lubricating oils, molten metal andthe like. It is conceivable to utilize finely powdered or minute ballsof heat conducting materials or combinations of finely powdered orminute balls of heat conducting materials and suitable liquids. It isessential, however, for these purposes that the heat conductingmaterials in the roll will be uniformly distributed on the inside of thesurface of the roll and will not interfere with the rotation of theroll.

The means of heating the stationary heating core in the apparatus ofthis invention can be by electrical heating units or preferably by heatconducting materials passing through the core such as heating vapors orheating liquids.

The heat conducting materials used to heat or cool the heat radiatingcore can include a variety of materials such as lubricating oils, moltenmetal, dowtherm, steam, etc. to obtain the desired effect. Thepreferable method is to utilize a suitable heating vapor such as steamor a high temperature resistant lubricating oil. It should be obvious toone skilled in the art that the method of heating large quantities offluids provides one of the best types of control of temperature forminimum fluctuations.

The apparatus, as claimed herein, when used in a drawtwisting operation,especially for polyethylene terephthalate yarns or filaments, provideshigh uniform products such as uniform shrinkage properties, the samephysical properties etc. because of the maintenance of constanttemperatures used throughout the unit of feeder rolls as describedherein.

It is to be understood that the foregoing description is merelyillustrative of preferred embodiments of the invention of which manyvariations may be made by those skilled in the art within the scope ofthe following claims without departing from the spirit thereof.

What is claimed is:

1. A unit of uniformly heated rolls comprising a plurality of roll unitswherein each of said roll units comprises a hollow rotatable roll, astationary heat radiating core, said core projected within the hollowportion of said hollow rotatable roll substantially conforming to theshape of said hollow portion, means for heating said core and non-vaporheat conducting fluid-like material self contained within said hollowrotatable roll uniformly distributed and intimately contacting the innerwall of said hollow rotatable roll and outer portion of said stationarycore projected within said hollow rotatable roll by centrifugal forcewhile the roll is turning.

2. A unit of uniformly heated rolls comprising a plurality of roll unitswherein each of said roll units comprises a hollow rotatable roll, astationary heat radiating core containing a passageway for the flow ofheat conducting materials, said core projected within the hollow portionof said hollow rotatable roll substantially conforming to the shape ofsaid hollow portion, inlet and outlet means connected to the passagewayin said core for the flow of heat conducting materials and non-vaporheat conducting fluid-like material self contained within said hollowrotatable roll uniformly distributed and intimately contacting the innerwall of said hollow rotatable roll and outer portion of said stationarycore projected within said hollow rotatable roll by centrifugal forcewhile the roll is turning; a main inlet means connected to eachindividual inlet means within the stationary heating core of eachindividual hollow rotatable roll for the flow of heat conductingmaterials from the heating source and a main outlet means connected witheach individual outlet means within the stationary heating core of eachindividual hollow rotatable roll for the return flow of heat conductingmaterials to the heating source.

3. A unit of uniformly heated rolls comprising a plurality of roll unitswherein each of said roll units comprises a hollow rotatable roll, astationary heat radiating core containing a passageway for the flow ofliquid heat conducting materials, said core projected within the hollowportion of said hollow rotatable roll substantially conforming to theshape of said hollow portion, inlet and outlet means connected to thepassageway in said core for the flow of liquid heat conducting materialsand liquid heat conducting materials self contained within said hollowrotatable roll uniformly distributed and intimately contacting the innerwall of said rotatable roll and outer portions of said stationary corewithin said hollow rotatable roll by centrifugal force while the roll isturning; a main inlet means connected to each individual inlet meanswithin the stationary heating core of each individual hollow rotatableroll for the flow of liquid heat conducting materials from the heatingsource and a main outlet means connected with each individual outletmeans within the stationary heating core of each individual hollowrotatable roll for the return flow of liquid heat conducting materialsto the heating source.

4. A unit of uniformly heated rolls comprising a plurality of roll unitswherein each of said roll units comprises a hollow rotatable roll, astationary heat radiating core containing a passageway for the flow ofliquid heat conducting materials, said core projected within the hollowportion of said hollow rotatable roll substantially conforming to theshape of said hollow ortion, inlet and outlet means connected to thepassageway in said core for the flow of vapor heat conducting materialsand liquid heat conducting materials self contained within said hollowrotatable roll uniformly distributed and intimately contacting the innerwall of said rotatable roll and outer portions of said stationary corewithin said hollow rotatable roll by centrifugal force while the roll isturning; a main inlet means connected to each individual inlet meanswithin the stationary heating core of each individual hollow rotatableroll for the flow of vapor heat conducting materials from the heatingsource and a main outlet means connected with each individual outletmeans within the stationary heating core of each individual hollowrotatable roll for the return flow of vapor heat conducting materials tothe heating source.

5. A unit of uniformly heated rolls comprising a plurality of roll unitswherein each of said roll units comprises a hollow rotatable rollcontaining a rotatable shaft, a back plate attached to said hollowrotatable roll, a stationary heat radiating core containing a passagewayfor the flow of heat conducting materials, said core projected withinthe hollow portion of said hollow rotatable roll substantiallyconforming to the shape of said hollow portion and surrounding therotatable shaft projecting from said hollow rotatable roll, inlet andoutlet means connected to the passageway in said core for the flow ofheat conducting materials, non-vapor heat conducting fluid selfcontained within said hollow rotatable roll uniformly distributed andintimately contacting the inner Wall of said hollow rotatable roll andouter portions of said stationary core within said hollow rotatable rollby centrifugal force while the roll is turning; a drip ring assembly ofopposed portions located on said stationary core and confronting saidback plate of said hollow rotatable roll as to maintain and preventleakage of fluids within said hollow rotatable roll, a main inlet meansconnected with each individual inlet means within the stationary heatingcore of each individual hollow rotatable roll for the fiow of heatconducting materials from the heating source and a main outlet meansconnected with each individual outlet means within the stationaryheating core of each individual hollow rotatable roll for the returnflow of heat conducting materials to the heating source.

6. A heat transfer apparatus comprising a hollow rotatable roll, astationary heat radiating core, said core projected within the hollowportion of said hollow rotatable roll substantially conforming to theshape of said hollow portion, means for heating said core and nonvaporheat conducting fluid-like material self-contained within said hollowrotatable roll uniformly distributed and intimately contacting the innerwall of said hollow rotatable roll and outer portion of said stationarycore projected within said hollow rotatable roll by centrifugal forcewhile the roll is turning.

7. A heat transfer apparatus comprising a hollow rotatable roll, astationary heat radiating core containing a passageway for the flow ofheat conducting materials, said core projected with the hollow portionof said hollow rotatable roll substantially conforming to the shape ofsaid hollow portion, means to conduct heat to and from said core, meansto supply and withdraw heat conducting materials from the passageway ofsaid core, and non-vapor heat conducting fluid-like materialself-contained within said hollow rotatable roll uniformly distributedand intimately contacting the inner wall of said hollow rotatable rolland outer portion of said stationary core within said hollow rotatableroll by centrifugal force while the roll is turning.

8. A heat transfer apparatus comprising a hollow rotatable rollcontaining a rotatable shaft, a stationary heat radiating corecontaining a passageway for the flow of heat conducting materials, saidcore projected within the hollow portion of said hollow rotatable rollsubstantially conforming to the shape of said hollow portion, and saidcore completely surrounding said rotatable shaft projecting from saidhollow rotatable roll, inlet and outlet means connected to thepassageway in said core for the flow of heat conducting fluids andnon-vapor heat conducting material self-contained within said hollowrotatable roll uniformly distributed and intimately contacting the innerwall of said hollow rotatable roll and outer portion of said stationarycore within said hollow rotatable roll by centrifugal force while theroll is turning.

9. A heat transfer apparatus comprising a hollow rotatable rollcontaining a rotatable shaft, a back plate attached to said hollowrotatableroll, a stationary heat radiaing core containing a passagewayfor the flow of heat conducting material, said core projected within thehollow portion of said hollow rotatable roll substantially conforming tothe shape of said hollow portion and surrounding the rotatable shaftprojecting from said hollow rotatable roll, heat conducting fluidself-contained within said hollow rotatable roll uniformly distributedand intimately contacting the inner wall of said hollow rotatable rolland outer portion of said stationary core within said rotatable roll bycentrifugal force while the roll is turning, and a drip ring assemblylocated on said stationary core confronting said back plate to maintainand prevent leakage of fluids within said hollow rotatable roll.

10. The apparatus of claim 9 wherein the heat conducting fluid withinthe hollow rotatable roll is a lubricating oil.

References Cited by the Examiner UNITED STATES PATENTS 2,873,538 2/1959Shumaker -89 X 3,022,047 2/ 1962 Swaney 165-89 3,238,592 3/1966 Killoranet al. 2871 X FOREIGN PATENTS 1,186,750 2/1959 France.

1,323,071 2/1963 France.

ROBERT A. OLEARY, Primary Examiner. MEYER PERLIN, Examiner. T. W.STREULE, Assistant Examiner.

1. A UNIT OF UNIFORMLY HEATED ROLLS COMPRISING A PLURALITY OF ROLL UNITSWHEREIN EACH OF SAID ROLL UNITS COMPRISES A HOLLOW ROTATABLE ROLL, ASTATIONARY HEAT RADIATING CORE, SAID CORE PROJECTED WITHIN THE HOLLOWPORTION OF SAID HOLLOW ROTATABLE ROLL SUBSTANTIALLY CONFORMING TO THESHAPE OF SAID HOLLOW PORTION, MEANS FOR HEATING SAID CORE AND NON-VAPORHEAT CONDUCTING FLUID-LIKE MATERIAL SELF CONTAINED WITHIN SAID HOLLOWROTATABLE ROLL UNIFORMLY DISTRIBUTED AND INTIMATELY CONTACTING THE INNERWALL OF